Home Page       Tue Sep 2 14:15:44 JST 1997

When images are only used for a specific purpose

On the other hand, some organized sky survey projects are already working at some large observatories on discovering NEAs (Near Earth Asteroids) and supernovae, or traking known objects. Because those projects aim at discovery or observation, their all images should be examined and the following observations after discovery should be done properly. In addition, some teams including SOHO (SOlar and Heliospheric Observatory) are using a software to examine their images. Therefore they are out of the problems already mentioned in case of personal images. But the surveying images at observatories have another problem. That is, because the images are taken for a specific purpose, only information on the purpose is used and other information remain unused.

For example, the SOHO team, observing the sun with a coronagraph on a satellite, had only reported the existence of some evident kreutz comets at the WWW page, except for information on the sun. But they began to measure the positions and report the appearances of kreutz comets regularly to IAU center after discovery of comet C/1997 H2, which is not a kreutz member. They also completed an automated software to detect moving objects from images. Then they started to examine old images again and, as you know, discovered many kreutz comets.

In this case, the SOHO team began to examine their images also in a point of view of comets, not only the sun, their original purpose. So the information on comets that the SOHO team's images contain also becomes to utilized. However, this case is rare. Images are generally examined only for the specific purpose. Actually, some variable stars observers proposed the SOHO team's images also can be used to obtain data of variable stars at conjunction with the sun. It means there are still some information, such as on variable stars, remaining unused even in the SOHO's images.

Images for any purpose have various information. But the owner team of the images are often experts of the original purpose. They may be weak at obtain another information in a point of another view. In conclusion, constructing of a world wide database of images is required in order to access to all images. Then experts of each field can examine all images in a point of their own view and obtain significant information.